The winners of the 2012 National Geographic Photography Competition have been announced, and they are astounding.

Below you'll find a handful of our favorite images from winners in each of the competition's three entry categories: Nature, People and Places. (Be sure to click the photographer info beneath each image for a hi-res download.) Check out all of 2012's winners, honorable mentions, and viewers' choices — along with the 22,000 other entries from year's competition — at National Geographic.

The subject's name is Busaba, a well cared for Indochinese Tigress whose home is at Khao Kheow Open Zoo, Thailand. I had taken many portraits of Busaba previously and it was becoming more and more difficult to come up with an image that appeared any different to the others. Which is why I took to observing her more carefully during my visits in the hope of capturing something of a behavioural shot. The opportunity finally presented itself while watching Busaba enjoying her private pool then shaking herself dry. In all humility I have to say that Mother Nature smiled favourably on me that day!

Glacial ice washes ashore after calving off the Breiðamerkurjökull glacier on Iceland's eastern coast. During the waning light of summer this image was created over the course of a 4 minute exposure while the photographer backlit the grounded glacial ice with a headlamp for 2 of those 4 minutes.

Stilt fishing is a typical fishing technique only seen in Sri Lanka. The fishermen sit on a cross bar called a petta tied to a vertical pole planted into the coral reef. This long exposure shot shows how unstable their position is.

I was surrounded by thousands of fish that moved in synchrony because of the predation that was happening. It was an incredible experience.

The Matterhorn 4478 m at full moon.

A race that follows in the path of the famous explorer Roald Amundsen brings the contestants to the Hardangervidda Mountainplateu, Norway. 100km across the plateau, the exact same route Amundsen used to prepare for his South Pole expedition in 1911 is still used by explorers today. Amundsen did not manage to cross the plateau and had to turn back because of bad weather. He allegedly said that the attempt to cross Hardangervidda was just as dangerous and hard as the conquering of the South Pole. The group in the picture used the race as preparations for an attempt to cross Greenland.